The present invention relates to a fuel supplying apparatus for supplying atomized fuel to an internal combustion engine, and in particular, to a fuel atomizing apparatus utilizing an ultrasonic wave vibrator.
An apparatus for supplying atomized fuel to an internal combustion engine utilizing an ultrasonic wave vibrator is known from, for example Japanese Patent Laid-Open (Kokai) Publication No. 58-210354 (1983). In such an apparatus, in a driving method of driving the ultrasonic wave vibrator, in order to cope with a deviation of the resonance point caused when the ultrasonic wave vibrator is driven at a fixed frequency, the period of an applied voltage to the ultrasonic wave vibrator is changed at a predetermined interval of period.
In the prior art, however, since the driving frequency of the ultrasonic wave vibrator is changed alternately to increase and to decrease at a predetermined period interval and with a predetermined width, there is a drawback in that a period of time in which the driving frequency coincides with the resonance point is only a fraction of the whole driving time, and thus the efficiency of the overall apparatus is degraded.